Knowledge acquisition is the least systematized aspect of the development of knowledge-based systems. One reason for this is that the complexity of technological systems, such as those used in motor-vehicle production or in automation engineering, limits the possible ways in which knowledge engineers can intuitively perform the process of acquisition. In all phases of the development of expert systems, therefore, use must be made of knowledge acquisition tools. This article examines several major projects currently underway at Siemens that are aimed at addressing this problem.